Help with Power Supply

[zello]

I am setting up a Carrera d124 track with the new 30352 cpu & toys. Its over 100ft so i was adding power taps and hooking up an independent power supply. Even though its digital i was wiring it for possible analog use in the future so i have 4 wires on each tapped track. I must have done something wrong.
1. The track works with the 30352 CU plugged into the wall outlet and not connected to the track
2. the 30352 CU works when disconnected from the track but connected to the new MG Pro Series power supply.
3. The whole track has no shorts when connected to the new power supply and i put a straight in in place of the CU.
4. When i connect the CU to the track but dont put the plug into the CU in yet power the track from the taps there are no shorts.
5.once i put the plug into the 30352 CU while it connected to the rest of the track even with the CU in the off position i get a short. It can be plugged in and not connected to the track and it wont short.

Any ideas of whats wrong?

Thanks Rich Z

[356speedster]

Sounds like you have wired the track for dual use and originated the power taps from the CU?

Please explain how the track is wired.

[slotcardaniel]

Your plug is connected to a PS, have you checked you have the + and - wires correctly connected to the PS ?

Daniel

[zello]

Its wired like this:

1. wall outlet to
2. power supply - positive negative to
3. terminal strip 1 (Main Strip)

a. Positive side

i. 30352 CU Positive lead to cut off connector end.
ii. Terminal strip for analog car controller 1 (not attached yet just there for future use)
iii. Terminal strip for analog car controller 2 (not attached yet just there for future use)

b. Negetive side

i. 30352 CU Negative lead to cut off connector end.
ii. Terminal strip for analog car controller 1 (not attached yet just there for future use)
iii. Terminal strip for analog car controller 2 (not attached yet just there for future use)

4. Terminal strip 2 (Analog car controller 1)

a. Right now this is just a place holder terminal strip. I have no controllers hooked to it and wiring is just a to a, b to b, ect.
b. IN

i. Positive form main terminal strip 1
ii. Negative from main terminal strip 1

c. Out to main lane terminal strip 4

i. Lane 1 Positive
ii. Lane 1 Negative

5. Terminal strip 3 (Analog car controller 2)

a. Right now this is just a place holder terminal strip. I have no controllers hooked to it and wiring is just a to a, b to b, ect.
b. IN

i. Positive form main terminal strip 1
ii. Negative from main terminal strip 1

c. Out to main Power Tap terminal strip 4

i. Lane 2 Positive
ii. Lane 2 Negative

6. Terminal strip 4 (main Power Tap)

a. This is where my 4 power tap tie to
b. IN

i. Positive form Analog car controller 1 terminal strip 2
ii. Negative from Analog car controller 1 terminal strip 2
iii. Positive form Analog car controller 2 terminal strip 3
iv. Negative from Analog car controller 2 terminal strip 3

c. OUT

i. Goes to 4 separate straight tracks that have each have 4 power taps in them
ii. Lane 1 Positive from main power tap terminal switch 4
iii. Lane 1 Negative from main power tap terminal switch 4
iv. Lane 2 Positive from main power tap terminal switch 4
v. Lane 2 Negative from main power tap terminal switch 4

All power taps are set to go in a clockwize direction.

[MrFlippant]

It sounds like you've wired the track for analog, including running power from the PSU through controller stations to the rails. It's possible I misunderstood your wiring description, but I didn't see any indication of switches to cut off power for the analog system when using the digital one, and vice versa.

You can't have that AND a digital control unit live at the same time. You can't even have them connected at the same time, as power from the track in analog mode will feedback and mess up the CU. You need to have electrically isolated power from the CU when used for digital, and from the controller hookups when used in analog. In your case, that's a couple (or a few) BIG switches between the outputs of the CU and the controller stations and into the track itself. You're creating a hard, breaking switch between two sources (CU and analog stations) to a single receiver (the track).

[b.yingling]

Good catch there, Greg. I really couldn't follow the wiring description given above, but I guess it does read like a single power supply feeds the lanes and the CU all at the same time. Definite disaster recipe.

[zello]

That’s exactly what I did.

I have read a ton of stuff about it and most of it is analog. I could find now wiring diagrams to add a power supply AND taps directly to a digital set up. So I thought that I would avoid any power draw issues by powering the track and the 30352 CU both. I figured that digital always powered the track at full power and the CU didn’t really regulate it except for overload protection. I thought the chips in the cars regulated the cars draw so they would be good. So with my incorrect thinking it’s the same track power and CU power this way it should be sure there are no power drops.

Thanks for the heads up. I will disconnect the CU and test it to see if its fried.

So to fix this I will disconnect the Main power tap Terminal Strip 4 from the power supply. I will reconnect it to the 30352 CU using power taps to the correct lanes.
So the order will now be

1. Wall to
2. Power supply to
3. Main Terminal strip 1 to

a. Analog controller 1 (not used yet) terminal strip 2
b. Analog controller 2 (not used yet) terminal strip 3
c. 30352 CU to(using a cut of end from the original power supply)

i. Main power tap terminal strip 4
ii. The 4 individual straight tracks I tapped

Does this sound correct?

[slotcardaniel]

I am lost....sorry

It is OK to have all the power taps as analog. Now, just plug your CU to the power supply and all will work.

If you want to have a dual track (analog and digital) go to the Digital forum and search the thread " dual box" from Burton Bruce. Use those key words. All is explained there.

Daniel

[356speedster]

You need to treat the CU and the analog hookup panel (driver stations) as separate units, and only connect one or the other to the track, not both at the same time.

The main reasons is that the CU connect both lanes into one single lane by using jumper cables between lane-1 and lane-2 in the CU track piece. To use the track for analog you must take the back cover off the CU track piece and move the track power cables from the rails and connect them to a 4PDT switch. Then wire track power cables from the switch to the rails (see below).

Here is a simple sketch I mocked up:



Another issue that cause problems is that on Carrera digital, the left rail is positive and the right rail is negative, this is opposite from the Carrera analog connection track piece, and other common analog wiring methods. This results in two issues:

1. in analog mode, the cars will travel in the opposite direction
2. Any digital accessories and LC's that is connected directly to the track will get power with opposite polarity than what they are designed for, when the track is in analog mode. This might destroy the accessories and LC's over time. This has not been proven, but it's a theory I have.

A simple solution is to cross the wires on the output side of the analog hookup panel (driver stations), this will ensure the track gets the same polarity as when in digital mode, but the direction of travel in analog mode will depend on the polarity of the controller/panel.

A better solution is to power all LC's and digital accessories directly from the CU output (make a power hub between the CU and the 4PDT switch in my sketch above). Then you can use a directional switch after the analog hookup panels and run the track analog in both directions without the risk of destroying the digital pieces.

As for power taps to distribute power evenly around the track, start the first tap on first normal track piece after the CU and make sure the lanes are isolated and the polarity is the same. Always connect the same rail to the same rail on the next tap.

Note: My sketch does not show how the analog driver stations should be wired, there are several guides on how to do this here on SCI and on the SCC website.

Tore

[zello]

Thanks i will go and try the digital end of the fix now. Analog stuff after.

Rich Z

[zello]

It all works just as i hoped. No dead spots. The cars fly! and the 30352 CU still works fine!!
I will try to add analog later.

Thanks Everyone.